Make DB Connect Delta Capable with External Sources: Part 2
- by Shreekant W. Shiralkar, Global Head, SAP Analytics CoE, Tata Consultancy
- Bharat Patel, SAP BW System Manager, Bharat Petroleum, India
- June 1, 2005
After you have connected your BW system to an external database using DB connect, you can make the DataSource delta capable with ABAP code using the time-stamp technique.
Most databases have a method for identifying new records and changes to the database whereby each new and changed record carries details of the time in year/month/day/hours/ minute/seconds. These details are also known as a time stamp. Oracle databases have a time stamp for all their tables unless they are specifically created otherwise. Using the time-stamp technique, delta records can be identified using the time-stamp details.
SAP BW from Release 3.0 on allows you to extract data from an external database using DB connect. However, delta capability is not automatically available. In part 1 of this series, we explained the first two steps for making an external DataSource delta capable: how to connect to the external database and how to create and configure the DataSource on the external system. In step 3, which we describe in this article, you make the DataSource delta capable with custom ABAP code.
We use the time-stamp technique, in which the delta records are identified using the date and time of creation or change captured by an application on the external system. Technically not a true delta, this method gives the user the delta records. In a true delta, the system tracks records that are already extracted. An overview of the coding and logic we used follows:
Would you like to see this full item?